(1) Field of the Invention
The present invention generally relates to instrumentation. More particularly it comprises thin film resistance temperature sensors for measuring heat flux to a surface at frequencies ranging from DC to over one hundred kilohertz.
(2) Description of the Prior Art
Accurate measurement of the heat transfer rate to turbine blading has long been recognized as a key to the improvement of high pressure turbine stages. The development of heat flux instrumentation for hot, warm and cold machines has therefore been an active research area. In hot turbines the harsh, oxidizing environment is a severely limiting constraint. Here thermal gradient devices such as Gardon gauges are becoming increasingly practical for measurement of the time average heat flux level.
The development of short duration turbine test facilities (30 to 700 ms test times) over the past decade has stimulated the development of heat flux instrumentation specifically optimized for the relatively benign environment (500.degree.-800.degree. K. gas temperatures) typical of these facilities. Calorimeter and thin film semi-infinite instruments have been extensively used in these applications.